Which of the following is not a CT feature ofAdrenal adenoma –

Adrenal adenoma on contrast-enhanced CT/MRI shows rapid uptake and relatively rapid washout of contrast material than do non adenomasQ. Adenoma: CT features Well defined/sharply defined  <5 cm in size Low attenuation (<10 HU) due to lipid content Mild homogenous enhancement Relatively rapid washout of contrast material (due to lack of large interstitial spaces Relatively rapid washout is characteristic of adenoma